[][Avoid strlen buff overflow]

[Description]
Add tail zero to avoid buff overflow in strlen

[Release-log]
N/A

Change-Id: Iefc346e7c30e33e7971e2d09c2acbe3457db104f
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/4734826
1 file changed